Cryptology ePrint Archive: Report 2006/045

Fully Collusion Resistant Traitor Tracing

Dan Boneh and Amit Sahai and Brent Waters

Abstract: We construct the first fully collusion resistant tracing traitors
system with sublinear size ciphertexts and constant size private keys.
More precisely, let $N$ be the total number of users. Our system
generates ciphertexts of size $O(\sqrt{N})$ and private keys of size
$O(1)$. We build our system by first building a simpler primitive
called private linear broadcast encryption (PLBE). We then show
that any PLBE gives a tracing traitors system with the same
parameters. Our system uses bilinear maps in groups of composite
order.